Rounded image using shaders

[AlterX]

Hi all,
I'm trying a piece of code got from another "thread":http://qt-project.org/forums/viewthread/7037/#152716 testing it on nokia n9 (but I think problem could be another one); at runtime I get this compilation error:
@
QGLShaderProgram::addShader: Program and shader are not associated with same context.
QGLShaderProgram::addShader: Program and shader are not associated with same context.
QGLShader::link: "Link Error: Vertex shader is missing.
Link Error: Fragment shader is missing.
"
ShaderEffectItem: Shader compilation failed:
"Link Error: Vertex shader is missing.
Link Error: Fragment shader is missing.
"
QGLShader::link: "Link Error: Vertex shader is missing.
Link Error: Fragment shader is missing.
"
QGLShaderProgram::uniformLocation( qt_ModelViewProjectionMatrix ): shader program is not linked
QGLShaderProgram::addShader: Program and shader are not associated with same context.
QGLShaderProgram::addShader: Program and shader are not associated with same context.
QGLShader::link: "Link Error: Vertex shader is missing.
@

I've put in my project all Nokia suggested stuff to use shaders.

Thanks in advance